package com.dd.census.tools;

import org.springframework.beans.BeansException;
import org.springframework.beans.factory.NoSuchBeanDefinitionException;
import org.springframework.beans.factory.config.BeanFactoryPostProcessor;
import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
import org.springframework.stereotype.Component;

@SuppressWarnings("unchecked")
@Component
public class SpringUtils implements BeanFactoryPostProcessor {

	 private static ConfigurableListableBeanFactory beanFactory; // Spring应用上下文环境

	    @Override
	    public void postProcessBeanFactory(ConfigurableListableBeanFactory beanFactory) throws BeansException {
	        SpringUtils.beanFactory = beanFactory;
	    }

	    /**
	     * 获取对象
	     *
	     * @param name
	     * @return Object 一个以所给名字注册的bean的实例
	     * @throws BeansException
	     *
	     */
	    public static <T> T getBean(String name) throws BeansException {
	        //首字母默认小写
	        name=lowerCaseInit(name);
	        if (containsBean(name)) {
	            return (T) beanFactory.getBean(name);
	        }else{
	            return null;
	        }
	    }

	    /**
	     * 获取类型为requiredType的对象
	     *
	     * @param clz
	     * @return
	     * @throws BeansException
	     *
	     */
	    public static <T> T getBean(Class<T> clz) throws BeansException {
	        T result = (T) beanFactory.getBean(clz);
	        return result;
	    }

	    /**
	     * 如果BeanFactory包含一个与所给名称匹配的bean定义，则返回true
	     *
	     * @param name
	     * @return boolean
	     */
	    public static boolean containsBean(String name) {
	        return beanFactory.containsBean(name);
	    }

	    /**
	     * 判断以给定名字注册的bean定义是一个singleton还是一个prototype。
	     * 如果与给定名字相应的bean定义没有被找到，将会抛出一个异常（NoSuchBeanDefinitionException）
	     *
	     * @param name
	     * @return boolean
	     * @throws NoSuchBeanDefinitionException
	     *
	     */
	    public static boolean isSingleton(String name) throws NoSuchBeanDefinitionException {
	        return beanFactory.isSingleton(name);
	    }

	    /**
	     * @param name
	     * @return Class 注册对象的类型
	     * @throws NoSuchBeanDefinitionException
	     *
	     */
	    public static Class<?> getType(String name) throws NoSuchBeanDefinitionException {
	        return beanFactory.getType(name);
	    }

	    /**
	     * 如果给定的bean名字在bean定义中有别名，则返回这些别名
	     *
	     * @param name
	     * @return
	     * @throws NoSuchBeanDefinitionException
	     *
	     */
	    public static String[] getAliases(String name) throws NoSuchBeanDefinitionException {
	        return beanFactory.getAliases(name);
	    }

	    /**
	     *首字母小写
	     * @return:  小写的首字母
	     */

	    private static String lowerCaseInit(String str) {
	        if (str.length()>0) {
	            char c = str.charAt(0);
	            if (c >= 65 && c <= 90) {
	                int i = c + 32;
	                return ((char)i)+str.substring(1);
	            }else{
	                return str;
	            }
	        }else{
	            return  null;
	        }
	    }
}
